8965

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Number

$8965$ (eight thousand, nine hundred and sixty-five) is:

$5 \times 11 \times 163$


The $55$th octagonal number, after $1$, $8$, $21$, $40$, $65$, $\ldots$, $5985$, $6256$, $6533$, $6816$, $7105$, $7400$, $7701$, $8008$, $8321$, $8640$:
$8965 = \ds \sum_{k \mathop = 1}^{55} \paren {6 k - 5} = 55 \paren {3 \times 55 - 2}$


Also see